1. Technical Field
The present disclosure relates to an over current protection (OCP) test system for a switching power supply.
2. Description of Related Art
Many personal computers utilize a switching power supply for providing direct current (DC) power sources (e.g., 3V, 5V, 12V, etc.) to components thereof. The switching power supply usually has an OCP function to detect whether an output current to each of the components exceeds a preset tolerance value. If the output current exceeds the preset tolerance value, the switching power supply is automatically powered off to protect the components.
In order to provide users with qualified switching power supplies, the switching power supplies should pass OCP test. In typical OCP test systems, each of the power supplies is connected to an electric load. The electric load has a knob to adjust a resistance value of the electric load. An operator should operate the knob to steadily decrease resistance of the load, thus increasing current flowing to the load. However, the resistance value of the electric load does not vary linearly, and the variation of the current flowing to the electric load is not linear, which makes it difficult to test the power supplies in a consistent manner.
What is needed, therefore, is an OCP test system capable of automatically controlling linearly varying current flowing to an electric load.